Oxygen-enriched combustion system of pulverized coal fired boiler
By designing an oxygen-rich combustion system for pulverized coal boilers, using flue gas circulation pipelines and oxygen supply devices to achieve full mixing of high-temperature flue gas and oxygen, the problems of incomplete combustion of coal powder and large pollutant emissions in the existing technology are solved, and the effect of efficient combustion and diversified coal powder is achieved.
Patent Information
- Application Number
- CN202422023623.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-08-20
AI Technical Summary
When existing coal pulverized boilers burn inferior coal, they are not completely burned, resulting in low-coal pulverized combustion efficiency, increased pollutant emissions, and equipment restrictions lead to a single source of available coal pulverized and cannot be used for diversified coal pulverized.
An oxygen-rich combustion system for pulverized coal boilers is designed. Through the flue gas circulation pipeline and oxygen supply device, the high-temperature flue gas and oxygen are fully mixed, and then mixed with air to form oxygen-rich gas, which improves combustion efficiency and reduces pollutant emissions.
It improves the combustion efficiency of coal powder, reduces pollutant emissions, has a wide range of applications, can be applicable to a variety of coal types, and improves the coal use channels for coal powder boilers.
Smart Images
Figure CN223050012U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of pulverized coal boilers, and particularly relates to an oxygen-enriched combustion system for a pulverized coal boiler. Background Art
[0002] A pulverized coal boiler is a boiler device that uses pulverized coal as fuel. The combustion characteristics of a pulverized coal boiler are that pulverized coal enters the combustion chamber and burns in a suspended state. Therefore, a pulverized coal boiler has the characteristics of rapid, complete combustion, large capacity, high efficiency, and wide adaptability to coal types.
[0003] However, in the current boiler pulverized coal combustion power generation technology, the emissions of high carbon dioxide and nitrogen oxides pose a great threat to the environment. When a pulverized coal boiler burns inferior coal, the mechanical incomplete combustion loss generated by the boiler will increase, resulting in a lower burnout efficiency of pulverized coal, an increase in pollutant emissions, and being limited by existing equipment, resulting in a single source of applicable pulverized coal and being unable to be applicable to diverse pulverized coal. Summary of the Utility Model
[0004] In order to solve the above technical problems existing in the prior art, the utility model provides an oxygen-enriched combustion system for a pulverized coal boiler.
[0005] The technical solution for the utility model to solve the above technical problems is as follows:
[0006] The utility model provides an oxygen-enriched combustion system for a pulverized coal boiler, which includes a boiler body provided with a flue gas outlet and an oxygen inlet; it further includes a flue gas circulation pipeline, one end of the flue gas circulation pipeline is communicated with the flue gas outlet, the other end is communicated with the oxygen inlet, and a recirculation fan, a flue gas-oxygen mixer and an air mixer are arranged on the flue gas circulation pipeline, and the flue gas sequentially passes through the recirculation fan, the flue gas-oxygen mixer and the air mixer; it further includes an oxygen supply device and a forced draft fan, the oxygen supply device is communicated with the flue gas-oxygen mixer for supplying oxygen to the flue gas-oxygen mixer; the forced draft fan is communicated with the air mixer for supplying air to the air mixer.
[0007] The oxygen-enriched combustion system for a pulverized coal boiler provided by the utility model improves the burnout efficiency of pulverized coal, reduces pollutant emissions, has a wide application range, can be applicable to various coal types, and improves the coal use channels of the pulverized coal boiler.
[0008] Based on the above technical solution, the utility model can further make the following technical improvements:
[0009] Further, it further includes a flue gas outlet pipeline, and an induced draft fan is arranged on the flue gas outlet pipeline, and the outlet of the induced draft fan is communicated with the inlet of the recirculation fan.
[0010] Further, an economizer, an air preheater, and a dust collector are sequentially connected on the flue gas outlet pipeline. The inlet of the economizer is connected to the flue gas outlet, and the outlet of the dust collector is connected to the inlet of the induced draft fan.
[0011] The beneficial effect of adopting the above further technical solution is that the high-temperature flue gas in the boiler flows through the economizer, the air preheater, and the dust collector in sequence through the flue gas outlet and then enters the induced draft fan, reducing the flue gas temperature and removing impurities such as dust carried in the flue gas at the same time.
[0012] Further, the flue gas-oxygen mixer includes a mixing box body and an oxygen supply mechanism connected to each other.
[0013] The beneficial effect of adopting the above further technical solution is that the flue gas-oxygen mixer realizes the full mixing of high-concentration oxygen and high-temperature flue gas, so that the oxygen content in the output mixed gas is higher than the oxygen content in the air. The flue gas flow rate introduced into the flue gas-oxygen mixer by the recirculation fan is related to the oxygen content provided by the oxygen supply device. If it is pure oxygen, more flue gas is required, while for a mixed gas with a small oxygen content, less flue gas is required, and the oxygen content provided by the oxygen supply device is determined according to the coal quality characteristics during pulverized coal combustion.
[0014] Further, the oxygen supply mechanism includes an oxygen main pipe and a number of oxygen branch pipes extending into the mixing box body, and nozzles are provided on the oxygen branch pipes. Oxygen enters the mixing box body through the oxygen main pipe, the oxygen branch pipes, and the nozzles in sequence.
[0015] Further, a number of the oxygen branch pipes are evenly distributed or spaced apart in the mixing box body.
[0016] Further, along the flow direction of the flue gas, the nozzles are provided on the leeward side of the oxygen branch pipes.
[0017] The beneficial effect of adopting the above further technical solution is to ensure the full and uniform mixing of high-concentration oxygen and high-temperature flue gas.
[0018] Further, one end of the mixing box body is provided with a flue gas inlet, and the other end is provided with a mixed flue gas outlet.
[0019] Compared with the prior art, the present invention has the following technical effects:
[0020] The pulverized coal boiler oxy-fuel combustion system provided by the present invention improves the burnout efficiency of pulverized coal, reduces pollutant emissions, has a wide application range, can be applicable to various coal types, and improves the coal use channels of pulverized coal boilers;
[0021] The high-temperature flue gas first flows through the flue gas-oxygen mixer and then through the air mixer, that is, the high-temperature flue gas is first mixed evenly with oxygen and then with air, so that before mixing with air, the oxygen has been fully mixed with the flue gas transported by the recirculation fan. As a result, the oxygen content in the mixed gas entering the boiler body subsequently can reach a predetermined concentration, the oxygen content in the mixed gas can be better controlled, and the oxygen content in the mixed gas can be controlled according to the coal quality characteristics during pulverized coal combustion. Thereby, the burnout efficiency of the pulverized coal is improved, pollutant emissions are reduced, it can be applied to a variety of coal types, and the coal use channels of the pulverized coal boiler are increased. Brief Description of the Drawings
[0022] Figure 1 It is a schematic structural diagram of the oxy-fuel combustion system of the pulverized coal boiler of the present invention;
[0023] Figure 2 It is the front view of the flue gas-oxygen mixer;
[0024] Figure 3 It is the top view of the flue gas-oxygen mixer;
[0025] Figure 4 It is Figure 3 The cross-sectional view along the A-A direction in
[0026] Reference Signs:
[0027] 1. Boiler body; 2. Recirculation fan; 3. Flue gas-oxygen mixer; 4. Air mixer; 5. Oxygen supply device; 6. Blower; 7. Induced draft fan; 8. Economizer; 9. Air preheater; 10. Dust collector; 11. Mixing box; 12. Oxygen main pipe; 13. Oxygen branch pipe; 14. Nozzle; 15. Oxy-fuel gas pipeline. Detailed Embodiments
[0028] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiments, this does not mean that the features of this invention are limited to this implementation manner. On the contrary, the purpose of introducing the invention in conjunction with the implementation manner is to cover other alternatives or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without these details. In addition, in order to avoid confusing or obscuring the key points of the present invention, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.
[0029] See Figure 1, an oxygen-enriched combustion system for a pulverized coal boiler, comprising a boiler body 1, on which a flue gas outlet and an oxygen inlet are provided; further comprising a flue gas outlet pipeline and a flue gas circulation pipeline, one end of the flue gas outlet pipeline is communicated with the flue gas outlet, one end of the flue gas circulation pipeline is used for inputting flue gas, and the other end is communicated with the oxygen inlet through an oxygen-enriched gas pipeline 15; a economizer 8, an air preheater 9, a dust collector 10 and an induced draft fan 7 are sequentially arranged on the flue gas outlet pipeline, a recirculation fan 2, a flue gas-oxygen mixer 3 and an air mixer 4 are sequentially arranged on the flue gas circulation pipeline, further comprising an oxygen supply device 5 and a forced draft fan 6, the oxygen supply device 5 is communicated with the flue gas-oxygen mixer 3 for supplying oxygen to the flue gas-oxygen mixer 3, the forced draft fan 6 is communicated with the air mixer 4 for supplying air to the air mixer 4, and measuring and monitoring equipment is also arranged on the pipeline to ensure the safe operation of the system; the high-temperature flue gas comes out from the flue gas outlet and then passes through the economizer 8, the air preheater 9, the dust collector 10, and the induced draft fan 7 in sequence and is discharged, at this time the temperature of the flue gas decreases; then the recirculation fan 2 extracts part of the flue gas output by the induced draft fan 7 into the flue gas-oxygen mixer 3, and in the flue gas-oxygen mixer 3, the flue gas is fully and evenly mixed with the oxygen transported by the oxygen supply device 5; the mixed gas after mixing enters the air mixer 4 and is mixed with the air transported by the forced draft fan 6, thereby forming oxygen-enriched gas; the oxygen-enriched gas enters the air preheater 9, is preheated after heat exchange with the high-temperature flue gas, and then is transported to the oxygen inlet through the oxygen-enriched gas pipeline 15.
[0030] The flue gas first flows through the flue gas-oxygen mixer 3 and then through the air mixer 4, that is, the flue gas is first evenly mixed with oxygen and then mixed with air, so that before mixing with air, the oxygen and the flue gas have been fully mixed, which can make the oxygen content in the mixed gas entering the boiler body 1 subsequently reach a predetermined concentration, the oxygen content can be better controlled, thereby improving the burnout efficiency of the pulverized coal, reducing pollutant emissions, and being able to reasonably control the oxygen content according to different coal types, being applicable to a variety of coal types, and improving the coal use channels of the pulverized coal boiler.
[0031] The air preheater 9 is provided with a flue gas inlet, a flue gas outlet, a mixed gas inlet and a mixed gas outlet. The economizer 8 is provided with a flue gas inlet and a flue gas outlet. The flue gas inlet of the economizer 8 is communicated with the flue gas outlet of the boiler body 1. The flue gas outlet of the economizer 8 is communicated with the flue gas inlet of the air preheater 9. The flue gas outlet of the air preheater 9 is communicated with a dust collector 10 for discharging the cooled flue gas. The mixed gas inlet of the air preheater 9 is communicated with the outlet of the air mixer 4. The mixed gas outlet of the air preheater 9 is communicated with an oxygen-enriched gas pipeline 15. The oxygen-enriched gas pipeline 15 is communicated with the oxygen inlet of the boiler body 1. The oxygen-enriched gas and the high-temperature flue gas exchange heat in the air preheater 9 to cool the high-temperature flue gas. At the same time, the oxygen-enriched gas is preheated, saving energy, making the pulverized coal easy to ignite, burning stably and improving the combustion efficiency.
[0032] See Figures 2-4 , the flue gas-oxygen mixer 3 includes a mixing box body 11 and an oxygen supply mechanism. The mixing box body 11 is provided with a flue gas inlet and a mixed flue gas outlet. The flue gas inlet is opened at the lower part of the mixing box body, and the mixed flue gas outlet is opened at the upper part of the mixing box body. Figure 2 The arrow direction in [reference figure] represents the flowing direction of the flue gas.
[0033] The oxygen supply mechanism includes an oxygen main pipe 12 and a plurality of oxygen branch pipes 13 extending into the mixing box body 11. Nozzles 14 are opened on the oxygen branch pipes 13. Oxygen enters the mixing box body 11 through the oxygen main pipe 12, the oxygen branch pipes 13 and the nozzles 14 in sequence. The plurality of oxygen branch pipes 13 are all communicated with the oxygen main pipe 12 or the oxygen branch pipes 13 are communicated with each other and then communicated with the oxygen main pipe 12 as long as the oxygen transported from the oxygen supply device 5 can be transported from the oxygen main pipe 12 to the oxygen branch pipes 13. The plurality of oxygen branch pipes 13 are evenly distributed or spaced in the mixing box body 11, and the extending direction of the oxygen branch pipes 13 is orthogonal to the flowing direction of the flue gas. Along the flowing direction of the flue gas, the nozzles 14 are opened on the leeward side of the oxygen branch pipes 13 to realize the full mixing of oxygen and high-temperature flue gas.
[0034] The pulverized coal boiler oxygen-enriched combustion system provided by the present invention improves the burnout efficiency of pulverized coal, reduces pollutant emissions, has a wide application range, can be applicable to various coal types, and improves the coal-using channels of pulverized coal boilers.
[0035] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A pulverized coal boiler oxygen-enriched combustion system, characterized in that: It includes a boiler body, which is provided with a smoke outlet and an oxygen inlet; it also includes a smoke circulation pipeline, one end of which is connected to the smoke outlet, and the other end of which is connected to the oxygen inlet, and the smoke circulation pipeline is provided with a recirculation fan, a smoke-oxygen mixer and an air mixer, and the smoke passes through the recirculation fan, the smoke-oxygen mixer and the air mixer in sequence; it also includes an oxygen supply device and an air blower, the oxygen supply device is connected to the smoke-oxygen mixer and is used to provide oxygen to the smoke-oxygen mixer; the air blower is connected to the air mixer and is used to provide air to the air mixer.
2. The pulverized coal boiler oxygen-enriched combustion system according to claim 1, characterized in that: It also includes a smoke outlet pipeline, on which an induced draft fan is arranged, and the outlet of the induced draft fan is connected to the inlet of the recirculation fan.
3. The pulverized coal boiler oxygen-enriched combustion system according to claim 2, characterized in that: The flue gas outlet pipeline is also provided with an economizer, an air preheater and a dust collector which are connected in sequence. The inlet of the economizer is connected to the flue gas outlet, and the outlet of the dust collector is connected to the inlet of the induced draft fan.
4. The pulverized coal boiler oxygen-enriched combustion system according to claim 1, characterized in that: The smoke-oxygen mixer comprises a mixing box and an oxygen supply mechanism which are connected to each other.
5. The pulverized coal boiler oxygen-enriched combustion system according to claim 4, characterized in that: The oxygen supply mechanism includes an oxygen main pipe and a plurality of oxygen branch pipes extending into the mixing box, and the oxygen branch pipes are provided with nozzles. The oxygen passes through the oxygen main pipe, the oxygen branch pipes and the nozzles in sequence and enters the mixing box.
6. The pulverized coal boiler oxygen-enriched combustion system according to claim 5, characterized in that: The plurality of oxygen branch pipes are evenly or spaced apart in the mixing box.
7. The pulverized coal boiler oxygen-enriched combustion system according to claim 5, characterized in that: Along the flow direction of the flue gas, the nozzle is opened on the leeward side of the oxygen branch pipe.
8. The pulverized coal boiler oxygen-enriched combustion system according to claim 4, characterized in that: One end of the mixing box is provided with a smoke inlet, and the other end is provided with a mixed smoke outlet.